Method of cutting slots in metal



Original application fled September 29, 1928, Serial No. 885,848.Divided and thin application flied July the tip are four heatingPatented Dec. 9, 1930 UNITED STATES PATENT orFlcE cmnnnon .1. COBEBLY,or L08 mamas, cams-01mm, xssronoa '10 xosn, me, or nunmeron max,camromvm, A conroimrion or canrroanra METHOD OI CUTTING SLOTS IN METAL10, 1929. Serial No. 377,183.

My invention relates to the art of cutting slots in metal plates andparticularly to the art of cutting slots in oil well casing, and is adivision of my co-pending application filed September 29, 1923, Serial N0. 665,648, entilted Converging jet cutting tip for cutting torches andmethod of using same.

It is generally necessary in the production of oil to provide a steelcasing or pipe which extends from the surface of the ground down intothe oil sand, and which is perforated where it extends into the oil sandto allow the oil to pass therethrough, the perforations through whichthe oil enters the well being sufficiently small to exclude the coarsesan and gravel surrounding the casing. It has been found that oil wellcasing can be connomically perforated by means of an oxygen cuttingtorch before being placed in the well. It has also been found that it ishighly desirable that the slots cut in the casingbe of a keystone-shapedsection, that is to say, that the slots be narrower at the outer surfaceof the pipe than at the inner, as it has been found that such slots aremuch less likely to clog than slots having parallel sides.

It is an object of my invention to provide a new method by which kestone-shaped slots can be produced in oil we 1 casing.

Further objects and advantages will be made evident hereinafter.

-Referring to the drawings which are for illustrative purposes only,

Fig. 1 is a cross section through a preferred embodiment of tip utilizedin practicing my invention.

Fig. 2 is a section on a plane represented by the line 2--2 of Fig. Iviewed in the direction of the arrows.

Fig. 3 is a view on a smaller scale showing a cutting torch utilized inpracticing my invention in operation.

In practicing my invention, I employ a tip 11 having a conical head 12,which is adapted to be secured in an oxygen cutting torch in theconventional manner. Extending through orifices 13 and two cuttingorifices 14. The heating orifices 13 are supplied with a mixture ofoxygen and a combustible gas in the usual manner, and the torch is soarranged as to also supply oxygen to the cutting orifices 14.

My novel process for cutting keystone shaped slots in metal involvesforming a plurality of jets of oxygen approaching each other andcombining at a given point to form a single jet and passing the singlejet through the metal and moving it to form a slot, the single jetcutting slot walls which diverge relative to each other.

A tip designed to cutoil well casing in ac! cordance with my improvedprocess may have the following dimensions theheating orifices 13 mayhave uniform diameter of .024 of an inch, the cutting orifices 14 havinga uniform diameter of .028 of an inch. The cutting orifices 14, at thepoint where they emerge from the tip, preferably have a center distanceof .056 of an inch, the angle between the cutting orifices 14 being 31/2 degrees. Operating on 7 16 inch material, that is to say, pipe.which is 7/16 inch thick, it is possible to cut a slot 1/16 inch thickat the outside of the pipe and.

5/64 inch thick at the inner surface of the pipe. The converging jets 23and 24 from the orifices 14 forma fan-shaped jet 25, having its greatestdimension at right angles to the lane of the paper as viewed in Fig. 1.This ame, spreading as it leaves the tip, tends to undercut the pipe inthe manner shown in Fig. 3, producing the sides of the slot and causinga relative movement between said metal and said jet. This slot, as shownby Fig. 3, is of keystone shape that is, it is narrower at the outersurface of the pipe than at the inner surfafie,'the sides 20 and 21being inclined to each ot er.

This form of slot is particularly valuable when applied to oil wellcasing, as material entering the slot through the narrow outer openingmust pass through the slot and cannot lodge therein and clog the slot.

By forming the slots with a jet of definite form, it is possible to forma slot of uniform width and form throughout its length.

I have found that by cutting slots by my method, not only is a veryuniform slot produced, but the action of the cutting jet hardens thesurface of the metal and increases its strength.

' being formed by slots in metal which consists in I claim as myinvention:

1. A process of cutting keystone-shaped slots in metal which comprisespassing a cutting jet throu b said metal. said cutting jet being formed%y a plurality of non-parallel jets so set as to cause said cutting jetto form the sides of the slot; and causing a relative movement betweensaid metal and said jet.

2. A process of cutting keystone-shaped slots in metal which comprisespassing a cutting jet through said a plurality of converglng jets so setas to cause said cutting jet to form the sides of the slot; and causinga relative movement between said metal and said jet.

3. A process for cutting keystone-shaped slots in metal which consistsin forming a plurality of jets of oxygen approaching each other andcombining at a given point to form a single jet, passing said single jetthrough said metal, and moving said single jet to form a slot, saidsingle jet cutting slot walls which diver e'relative to each other.

4. g process for cutting keystone-shaped orming a plurality ofconverging jets of oxygen which intersect at a given point to form asingle jet, passing said single et through said metal, and moving saidsingle jet to form a slot, said single jet cuttin slot walls whichdiverge relative to each ot er.

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 3rd day of July, 1929. j CLARENCE J COBERLY.

metal, said cutting jet-

